Self destructive torpedo



June 20, 1961 w. B. ELMER 2,988,991

SELF DESTRUCTIVE TORPEDO Filed Oct. 31, 1945 Alllllllllll'l'l' INVENTOR ATTORNEY United States Patent O 2,988,991 SELF DESTRUCTIVE TORPEDO William B. Elmer, Lakewood, Ohio, assignor to Westinghouse Electric Corporation, East Pittsburgh, -Pa., a corporation of Pennsylvania Filed Oct. 31, 1945, Ser. No. 625,904 6 Claims. (Cl. 102-16) My invention relates to torpedoes and more particularly to a torpedo provided with means for self-destruction.

Some types of torpedoes are inherently designed to be positively buoyant. This is particularly true of torpedo mines moored at some convenient. place where enemy shipping may be intercepted. Every precaution should be taken to prevent torpedoes particularly of new types from falling into enemy hands. Buoyant torpedoes, after an unsuccessful run, can be captured. Our armed forces have actually captured enemy torpedoes.

One object of my invention is the provision of selfdestruction of the torpedo in the event an unsuccessful run is made by the torpedo.

A more specific object of my invention is the provision of self-destructive features for a torpedo that function only after an unsuccessful run and are not actuated by broaching of the torpedo during a run.

The objects stated are merely illustrative. Other objects and advantages will become more apparent from a study of the following specification and the accompanying drawing, in which:

FIGURE 1 is a diagrammatic showing of the essential electrical features of my invention;

FIG. 2 shows a curve of aid in understanding of the explanations of my invention herein given.

I obtain the self-destruction feature by the addition of new electric circuits and elements designed and arranged to coact with the usual control elements so that selfdestruction occurs under certain conditions only.

The details of my invention can probably be best understood from a study of the sequence of operation of the novel elements and such of the conventional control elements as coact with the novel elements.

When the torpedo T is fired from the tube 1 or is set in operation from its moored position, in the event the torpedo is used as a mine, the trigger switch contacts 4 and 5 of trigger switch 6 are closed. Closure of the contacts 4 and 5 establishes a circuit from the positive terminal 2 of the battery B, through conductor 3, contacts 4 and 5 of the trigger switch 6, actuating coil 7 of the main contactor 8 and conductor 9 to the negative terminal 10 of battery B.

Operation of contactor 8 establishes a circuit from the positively energized conductor 3 through contacts 11, the armature 13 of the propulsion motor M, and the motor field winding 14 to the negatively energized conductor 9.

Since the battery voltage is, at the starting. of the torpedo, at its maximum value, as at point- A. on curve C of FIG. 2, and since the motor is heavily loaded, a considerable voltage drop is established across the field 14. To take advantage of the voltage drop across field 14 and to make the self-destruction feature reliable, simple, and directly responsive to voltage changes taking place during a run of a torpedo, I connect the heating resistor 15' across the field winding 14 and also connect the actuating coil 16 of the instantaneous relay 17 across the field winding 14.

The heating resistor 15 is disposed in proximity of the bimetal element 18 arranged to operate contacts 25. When the heater 15 is energized at a selected value contacts 25 open.

As soon as the run is completed the voltage of the battery has dropped to a point, as D on curve C. The thermostatic device, comprising the heating resistor 15 and bimetal 18, is designed to close the contacts 25. Since the voltage across the field 14 also affects the actuating coil 16 of the instantaneous relay 17 this relay also closes its contacts 27 after an unsuccessful run has been completed.

The instantaneous relay 17 is designed to instantly open the contacts 27 when the torpedo gets underway. Any delay in the opening of contacts 25 thus does not effect self-destruction. The instantaneous relay similarly instantaneously closes the contacts 27 when the voltage across field 14' drops to a given value, namely the voltage drop that is available at the end of an unsuccessful run.

Duringta normal and intended operation of the torpedo the detonating squib, or electric ignitor 21 is energized, either by contact with the target or by devices responsive to the proximity of the target, or both, through the operation of the Exploder Mechanisms. Operation of the Exploder Mechanisms establishes a circuit from the energized conductor 3, through contacts 11, conductors 19 and 20, the Exploder Mechanisms and squib 21 to the conductor 9.

To provide for the firing, or energizat-ion, of the squib 21 at the end of an unsuccessful run, I provide a circuit in parallel to the Exploder Mechanisms. This parallel circuit may be traced from energized conductor 19 through the contacts 22 of a depth responsive device 23, conductor 24, contacts 25 of the thermostatic time delay device 26, contacts 27 of the instantaneous relay 17 and squib 21 to the conductor 9.

When the torpedo is used as a mine and released for operation toward the target from a considerable depth it is apparent that contacts 22 will remain open for some time. This time period is more than ample, if the thermostatic device is properly selected, to assure that contacts 25 are open before the torpedo rises to the selected depth of its normal run. Further the normal depth of the torpedo during a run is such that contacts 22 remain open. Under these conditions the instantaneous relay is not needed.

My invention is not limited to the particular time limit device shown but contacts 25 may be operated to close at the end of an unsuccessful run under the control of a timing motor, or clock mechanism.

The depth responsive device 23 closes its contacts 22 when the torpedo is at a depth of five feet or less. During a normal run, namely while the run is still in progress, the depth control devices operating on the elevator rudders and not forming part of this invention, keep the torpedo at a depth greater than the five foot level. There is thus no danger of firing the squib during the normal run.

During a normal run the torpedo may broach. Broaching will close contacts 22 and since the voltage drop across the field 14 drops to a low value while the motor is thus unloaded by the free spinning of the propellers in the air, the contacts 27 also close. The contacts 25, being much slower in action by reason of the time delay characteristics of the thermostatic device 26, remain open. Broaching, therefore, does not fire the squib 21.

At the end of an unsuccessful run the battery voltage drops to point D with the result that both the instantaneous relay 17 as well as the thermostatic device close their contacts 27 and 25, respectively. The torpedo also surfaces and contacts 22 are thus closed. The squib is thus fired and the consequent self-destruction takes place.

From the foregoing it should be apparent that the con tactor 8 must be designed to have a much lower drop-out voltage, as voltage F from FIG. 2, than the voltages E and D the drop-out voltages for the thermostatic device 26, and relay 17, respectively.

During the starting of the torpedo contacts 25 are not immediately opened and it may happen that contacts 22 also close. Firing of the squib is, however, prevented by the instantaneous relay 17 which opens the contacts 27.

While I have shown one circuit arrangement, it is, of course, apparent, particularly after having had the benefit of the teachings of my invention that other circuit arrangements may be devised for the same or substantially the same purposes. I, therefore, do not wish to be limited to the specific showing made but wish to be limited only by the scope of the claims hereto appended.

I claim as my invention:

1. In a buoyant torpedo, in combination, a source of electric energy, a propulsion motor having a field winding, switching means, set in operation when the torpedo is to proceed toward the target, for connecting the motor to the source of electric energy, a thermostatic time limit device having an electric heater connected across the motor field winding to thus be energized as a function of the voltage drop across the field winding, a switch coupled to the thermostatic device and adapted to close by reason of the voltage drop across the field winding at the end of an unsuccessful run of the torpedo, an electric ignitor for the explosive charge in the torpedo, means responsive to the proximity of the target to the torpedo for energizing the ignitor, a device responsive to pressure, contacts connected to said device responsive to pressure and adaptedto close when the torpedo is at a relatively small depth, said contacts of the depth responsive device, and said switch of the thermostatic device being connected in series with the ignitor, but in parallel with the device responsive to the proximity of the target, so that said ignitor is energized at the end of an unsuccessful run to provide self-destruction of the torpedo.

2. In a buoyant torpedo, in combination, a source of electric energy, a propulsion motor having a field winding, switching means, set in operation when the torpedo is to proceed toward the target, for connecting the motor to the source of electric energy, a thermostatic time limit device having an electric heater connected across the motor field winding to thus be energized as a function of the voltage drop across the field winding, a switch coupled to the thermostatic device and adapted to close by reason of the voltage drop across the field winding at the end of an unsuccessful run of the torpedo, an electric relay having switch contacts disposed in series with said switch and having its actuating coil connected across the motor field winding, said relay being of the instantaneous type to open its switch contacts the instant voltage is applied across the field winding and to close its contacts at a selected drop of voltage across the field winding, an electric ignitor for the explosive charge in the torpedo, means responsive to the proximity of the target to the torpedo for energizing the ignitor, a device responsive to pressure, contacts connected to said device responsive to pressure and adapted to close when the torpedo is at a relatively small depth, said contacts of the depth responsive device, said switch of the thermostatic device and switch contacts of the relay being connected in series with the ignitor, but in parallel with the device responsive to the proximity of the target, so that said ignitor is energized at the end of an unsuccessful run to provide self-destruction of the torpedo.

3. In a normally buoyant torpedo, in combination, igniter means for firing the explosive charge of the torpedo in response to some physical elTect produced by the target on the igniter means, a source of electric energy, an energizing circuit for the igniter means for firing the explosive charge independently of any physical efiects produced by a target, said energizing circuit including a first switch and a second switch, a time delay device operable to close the first switch a selected time interval after starting of the torpedo, and pressure responsive means for closing said second switch to thus close the energizing circuit for the igniter should the first switch be also closed at the time the second switch is closed.

4. In a torpedo carrying an explosive charge and having conventional propulsion means set in operation upon launching of the torpedo, in combination, a source of electric energy in the torpedo, an electrically operable igniter for elfecting the detonation of the explosive charge upon connection of the igniter to the source of electric energy, two energizing circuits for the igniter, one of said energizing circuits including exploder mechanisms responsive to effects produced by the target for closing one of said circuits, the other of said energizing circuits including a first switch and a second switch which switches when simultaneously closed effect cnergization of the igniter, timing means set in operation by the launching of the torpedo for closing the first switch a time period after launching of the torpedo, and means responsive to depth of the torpedo below the sea surface for closing the second switch to thus complete the energizing circuit for the igniter upon the joint action of the timing means and depth responsive means.

5. In a normally buoyant torpedo containing an explosive charge, in combination, a source of electric energy, a propulsion motor connected to said source of energy upon starting of the torpedo, electric current responsive igniter means for firing the explosive charge of the torpedo in response to some physical effect produced by the target on the igniter means for effecting the firing of the explosive charge of the torpedo, a first switch, a time delay device set in operation upon starting of the torpedo and operable to open said first switch and then to close said first switch a certain time period after starting of the torpedo, a second switch, depth responsive means operable to close the second switch, and a third switch in operation adapted to close responsive to a given change in voltage of said source of electric energy, said electric current responsive igniter being interconnected with said source of electric energy and said switches to become energized to fire the explosive charge upon the closure of all three switches.

6. In a normally buoyant torpedo containing an explosive charge, in combination, igniter means for firing the explosive charge in response to the proximity of the target to the torpedo, means for also effecting the operation of the igniter means after an unsuccessful run of the torpedo, said last named means including a time delay device eifecting set-up operation a time period after starting of the torpedo, and depth responsive means for effecting a second set-up operation when the torpedo surfaces after an unsuccessful run, said igniter means being interconnected with said time delay device and said depth responsive device to be effective to fire said explosive charge upon the joint action of said set-up operations.

References Cited in the file of this patent UNITED STATES PATENTS 1,626,794 Dieter May 3, 1927 2,060,206 Hammond Nov. 10, 1936 FOREIGN PATENTS 376,987 Italy Dec. 4, 1939 

